JPH0529433Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum pressure control valve used when vacuum pressure is used to attract and release objects.

[Prior Art] Conventionally, as shown in FIG. 3, two electromagnetic valves 1 and 2 are used as vacuum pressure control valves when vacuum pressure is used to adsorb and release objects. The electromagnetic valves 1 and 2 are two-port valves having a port communicating with a suction pad 3 and a port communicating with a vacuum source 4 such as a vacuum pump or a compressed air source 5 such as an air compressor or an air receiver. ing.

In such a vacuum pressure control valve, when the solenoid a of the electromagnetic valve 1 is energized in the illustrated inactive state, the suction pad 3 communicates with the vacuum source 4, so that the desired article can be suctioned and held by the vacuum pressure. can. Furthermore, when the solenoid a is de-energized and the solenoid b of the electromagnetic valve 2 is energized, the suction pad 3 is communicated with the compressed air source 5, so the vacuum pressure of the suction pad 3 is eliminated by the compressed air. The adsorbed items are released.

However, in the conventional vacuum pressure control valve described above, when the vacuum pressure is applied to the suction pad 3 to attract and hold the article, if the solenoid a of the solenoid valve 1 is demagnetized due to a power outage, etc., the suction pad 3 and the vacuum source 4 are cut off, the suction pad 3 loses its ability to suction and hold the article, potentially causing a serious accident.

In order to eliminate the drawbacks of the vacuum pressure control valve described above, the directional control valve 14 is operated by two 3-port pilot valves 11 and 12 that supply and discharge pilot fluid, as shown in FIG. A vacuum pressure control valve may be considered in which the pilot valve 12 is provided with a detent mechanism 15 for holding the switching position and a solenoid c for releasing the lock of the detent mechanism 15.

In this vacuum pressure control valve, pilot valve 1
Each of the solenoids a, b, and c in the valves 1 and 12 is de-energized, and the pilot chambers at both ends of the directional control valve 14 are opened to the atmosphere through the pilot valves 11 and 12.
As a result, when the switching valve 14 is in the neutral position shown, the ports communicating with the suction pad 3, the vacuum source 4, and the compressed air source 5 are all closed, so the suction pad 3 is free from vacuum pressure. It is in a resting state with no air pressure acting on it.

When solenoid b is energized in this state, pilot fluid from compressed air source 5 flows into pilot valve 12.
Since the suction pad 3 is supplied to the pilot chamber on the left side of the switching valve 14 through the switching valve 14, the suction pad 3 is communicated with the vacuum source 4 by switching the switching valve 14.

In this switching state, the pilot valve 12 is held in this position by the detent mechanism 15, so that
Even if the solenoid b is demagnetized due to a power outage or the like while the suction pad 3 is suctioning and holding an article, the suction pad 3 will not lose its ability to suction and hold the article.

Next, when the solenoid c is energized, the position holding by the detent mechanism 15 is released and the pilot valve 12 returns to the state shown in the figure, and the pilot fluid in the pilot chamber on the left side of the switching valve 14 is discharged to the atmosphere, so that the switching The valve 14 is returned to the illustrated neutral position by the biasing force of the spring.

Thereafter, when the solenoid a of the pilot valve 11 is energized, pilot fluid is supplied to the pilot chamber on the right side of the switching valve 14.
moves to the left and the suction pad 3 is communicated with the compressed air source 5, so that the article suctioned and held by the suction pad 3 is released. Next, when the solenoid a is de-energized, the pilot fluid in the pilot chamber on the right side of the switching valve 14 is discharged to the atmosphere through the pilot switching valve 11, so that the switching valve 14 is moved to the neutral position shown in the figure by the biasing force of the spring. , and the suction pad 3 returns to its resting state.

In the vacuum pressure control valve, the detent mechanism 15 maintains the pilot air supply position of the pilot switching valve 12 when the suction pad 3 and the vacuum source 4 are switched to communicate with each other in the direction switching valve 14. can eliminate the drawbacks of

However, the operation of the suction pad that suctions and releases the article generally requires the suction pad to be in a rest state between releasing the article and holding the article by suction, but the suction pad 3 Since the above-mentioned vacuum pressure control valve does not require a rest state, there is a waste of operation in which the suction pad 3 is put in a rest state where neither air pressure nor vacuum pressure is applied between the suction and holding of the article and the release thereof, and the pilot valve 12
Since it requires a separate solenoid C, it has the disadvantage of being expensive.

[Problems to be solved by the invention] The problems to be solved by the invention are to prevent the suction pad from losing its suction and holding function even if the solenoid is demagnetized due to a power outage, etc., and to release the suction and holding of the article. It is an object of the present invention to provide an inexpensive vacuum pressure control valve that eliminates wasteful operation due to intervening pauses of suction pads.

[Means for Solving the Problems] In order to solve the above problems, the vacuum pressure control valve of the present invention includes a main valve consisting of a 3-port 3-position switching valve, and a pilot switching valve for supplying and discharging pilot fluid to the main valve. A vacuum pressure control valve comprising: a supply port communicating with a compressed air source; an output port communicating with a suction pad; and a vacuum pressure port communicating with a vacuum pressure source; The main switching valve section is provided with a main switching valve section and a pressure receiving operation section, and the main switching valve section is set to a first switching position in which the output port is communicated with the vacuum pressure port by pilot fluid supplied and discharged from the pilot switching valve to the pressure receiving operation section. , a second switching position in which the output port is communicated with the supply port, and a neutral position in which communication between the remote ports is cut off, and the pilot switching valve has a pilot switching valve member and a pilot switching valve member. and a mechanical detent mechanism, and when the pilot switching valve member is in the first switching position by one of the electromagnetic switching valves, the pilot switching valve is connected to the pressure-receiving operating part of the main valve. Fluid is supplied to switch the main switching valve to the first switching position, and when the other electromagnetic switching valve is in the second switching position, pilot fluid is supplied to the pressure receiving part of the main valve to switch the main switching valve. The mechanical detent mechanism is characterized in that the mechanical detent mechanism maintains the pilot switching valve member in the first switching position at the switching position even during a power outage.

[Operation] When both solenoid switching valves are inoperative,
Since pilot fluid is not supplied to the pressure-receiving operating section of the main valve, the main switching valve section is in a neutral position where communication between the ports is cut off, and the suction pad is in a resting state.

If one of the solenoid switching valves is operated in this state,
The pilot switching valve member switches to a first switching position and a mechanical detent mechanism maintains this switching position. Additionally, when the pilot switching valve member switches to the first position, pilot air is supplied to the pressure receiving operating part of the main valve, so the main switching valve part switches to the first switching position and the output port becomes the vacuum pressure port. Communication occurs, and vacuum pressure acts on the suction pad.

In this case, the pilot switching valve member is held in the first switching position by the detent mechanism, so even if the electromagnetic switching valve loses its function due to a power outage, etc., the main valve will remain in the first switching position. is held.

Next, when one electromagnetic switching valve is deactivated and the other electromagnetic switching valve is activated, the position of the pilot switching valve member is released from being held by the detent mechanism, and the valve member is switched to the second switching position.
As a result, pilot air is supplied to the pressure-receiving operating section of the main valve, so the main switching valve section switches to the second switching position and the output port communicates with the supply port.
Compressed air acts on the suction pad.

When the other electromagnetic switching valve is deactivated, the main switching valve section of the main valve returns to its original neutral position, and the suction pad returns to its resting state.

[Embodiment] Figures 1 and 2 show an embodiment of the present invention, and this vacuum pressure control valve includes a main valve 20, a pilot switching valve 50 that supplies pilot air to the main valve 20, and a pilot switching valve 50 that supplies pilot air to the main valve 20. First and second electromagnetic switching valves 60a and 60b are provided for supplying and discharging control air to and from the valve 50.

The valve body 21 of the main valve 20 has a supply port P that communicates with the compressed air source 5, an output port A that communicates with the suction pad 3, and a vacuum pressure port R that communicates with the vacuum source 4. A main switching valve section having a valve section 22 and a vacuum pressure valve section 23, and a pressure receiving operation section 24 for driving the main switching valve section are provided.

The supply valve section 22 has a supply port P and an output port A.
The supply valve seat 26 is provided with a supply valve seat 26 that communicates with the supply valve seat 26.
A cylindrical back chamber having approximately the same diameter as the back chamber is formed at a position facing the supply valve seat 26, and a supply valve body 27 for opening and closing the supply valve seat 26 is slidably inserted into the back chamber. A main valve spring 28 that presses the valve against the supply valve seat 26 is compressed. In addition, the above-mentioned back chamber is
A communication hole provided in the supply valve body 27 communicates with the output port A side. A vacuum pressure valve section 23 formed coaxially with the supply valve section 22 has an output port A.
A vacuum pressure valve seat 29 is provided which communicates the vacuum pressure port R with the supply valve seat 26, and the vacuum pressure valve portion 29 is formed so as to face the supply valve seat 26. Further, a cylindrical back chamber is formed at a position facing the vacuum pressure valve seat 29 in the valve body 21, and the vacuum pressure valve seat 29 is provided in the back chamber.
A vacuum pressure valve body 30 that opens and closes the valve 9 is slidably inserted therein, and a main valve spring 31 that presses the vacuum pressure valve body 30 against the vacuum pressure valve seat 29 is compressed.
Note that the back chamber is communicated with the output port A side through a communication hole provided in the vacuum pressure valve body 30.

The pressure receiving actuator 24 that drives the supply valve section 22 and the vacuum pressure valve section 23 includes a rod 32 that is slidably inserted into the rod insertion holes of the supply valve body 27 and the vacuum pressure valve body 30, and the supply valve in the rod 32 body 2
A large diameter portion is formed in a portion between 7 and the vacuum pressure valve body 30. In the neutral state shown in FIG. 1, both the supply valve section 22 and the vacuum pressure valve section 23 are in a closed state, and when the rod 32 is in a downward movement state, the vacuum pressure valve body 30 is located below the rod 32. The supply valve body 27 maintains the closed state while allowing movement, and the main valve spring 28
The valve is opened downwardly against the biasing force of the rod 3.
2 is in the upwardly moved state, contrary to the above, the supply valve section 22 is closed and the vacuum pressure valve section 23 is opened.

The piston 34 to which the rod 32 is fixed defines a first pilot chamber 35 and a second pilot chamber 36 in the valve body 21, and is driven in the axial direction by the pressure difference between them. is in communication with a first pilot passage 37, and the second pilot chamber 36 is in communication with a second pilot passage 38, respectively. Therefore, the piston 34 and the rod 32 move downward when the pressure in the second pilot chamber 36 is greater than that in the first pilot chamber 35;
When it is small, it moves upwards.

On the other hand, the body of the pilot switching valve 50 is provided with a through hole in the axial direction into which a spool 52 constituting the pilot switching valve member is slidably inserted, and a first pressure chamber 54 is provided at one end of the through hole. A detent mechanism 55 is provided at the other end, and a second pressure chamber 56 is formed. Further, the body is provided with a pilot port Ac communicating with the first pilot passage 37 in the center, and an exhaust port Rc communicating with the exhaust passage 40 and a pressure port Pc communicating with the supply passage 39 on both sides thereof. The pressure port Pc is communicated via a pressure passage 53 with a required port in the electromagnetic switching valves 60a, 60b.

One end of the spool 52 is connected to the first pressure chamber 54,
The other end protrudes into the second pressure chamber 56, and their tips abut against pistons inserted into the pressure chambers 54, 56.

The detent mechanism 55 has a plurality of balls 57, . A mechanical detent mechanism for temporarily engaging and holding the spool 52 is constituted by the locking groove 58 formed in the spool 52 .

On the other hand, the electromagnetic switching valves 60a and 60b are well-known three-port electromagnetic valves consisting of valve mechanism parts 62a and 62b and electromagnetic parts 61a and 61b.
a, 62b have ports Pa, Pb communicating with the above-mentioned pressure passage 53, a port Aa communicating with the first pressure chamber 54, and a port Ab communicating with the second pressure chamber 56 and the second pilot passage 38. , electromagnetic section 61
A port Ra, which communicates with the atmosphere, is opened in the cover through the fixed cores 63a and 63b of a and 61b.
It is equipped with Rb.

When the electromagnetic switching valve 60a is not energized, the valve mechanism section 62a of the electromagnetic switching valve 60a uses a valve member provided on the movable core 64a to cut off communication between ports Pa and Aa, and to communicate between ports Aa and Ra. , When the electromagnetic section 61a is excited, the ports Pa and Aa are communicated with each other, and the ports Aa and Ra are disconnected from each other. Also, the valve mechanism section 62b of the electromagnetic switching valve 60b
Similarly to the switching valve 60a, by energizing and de-energizing the electromagnetic section 61b, port Ab is switched between ports Pb and Rb.
Switch to and connect.

Next, the operation of the above embodiment will be explained with reference to FIGS. 1 and 2.

In FIG. 1, both the electromagnetic parts 61a and 61b of the electromagnetic switching valves 60a and 60b are in a non-energized state, and the pressure chambers 54 and 56 at both ends of the pilot switching valve 50 are connected to ports Aa, Ra and Ab, Rb
The pressure port Pc of the pilot switching valve 50 is closed, and the pilot port Ac and exhaust port Rc communicate with each other. Therefore, the pilot chambers 35 and 36 of the main valve 20 communicate with the atmosphere from port Ab through port Rb and from pilot port Ac through exhaust port Rc, respectively, and the pressure receiving actuating portion 24 communicates with the atmosphere through port Rb and from pilot port Ac through exhaust port Rc, respectively.
8 and 31 in the neutral position, and the supply valve part 2
2. Since the vacuum pressure valve section 23 is closed and the main switching valve section is in the neutral position, the suction pad 3 is in a rest state where neither compressed air nor vacuum pressure is applied. In this case, the compressed air of the compressed air source 5 is supplied to the supply port P,
Supply passage 39, pressure port Pc and pressure passage 53
It is supplied to ports Pa and Pb through it.

When the electromagnetic section 61a of the electromagnetic switching valve 60a is energized in this state, ports Pa and Aa communicate with each other and pressure is supplied to the first pressure chamber 54 of the pilot switching valve 50, so that the spool 52 is pressed by the first piston. It slides to the right in the figure and switches to the first switching position.

When the spool 52 is switched to the first switching position, the pressure port Pc of the pilot switching valve 50 and the pilot port Ac communicate with each other, so that compressed air passes through the first pilot passage 37 and enters the first pilot chamber 35 of the main valve 20. Supplied. This allows the main valve 20
The piston 34 and rod 32 move upward in the figure, and the main switching valve part
Since the vacuum pressure from the vacuum source 4 acts on the suction pad 3, the suction pad 3 attracts and holds the desired article.

In this case, the spool 52 is held at the first switching position by pushing the balls 57, .
Even if the power to the main valve 20 is cut off, the output port A
The state is maintained at the first switching position where the vacuum pressure port R and the vacuum pressure port R communicate with each other. Therefore, when the suction pad 3 is suctioning and holding an article, the electromagnetic part 61a may be damaged due to a power outage or the like.
Even if the magnet is demagnetized, the suction pad 3 will not lose its suction and holding ability.

Next, when the electromagnetic section 61a is de-energized and the electromagnetic section 61b of the electromagnetic switching valve 60b is excited, ports Pb and Ab communicate with each other, so that compressed air is supplied to the second pressure chamber 56 and the second pilot A second pilot chamber 36 of the main valve 20 is also supplied through a passage 38.

On the other hand, by de-energizing the electromagnetic part 61a, the port
Communication between Pa and Aa is cut off and port Aa
Since Ra is in communication, the air in the first pressure chamber 54 is discharged to the atmosphere. Therefore, the spool 52 is pressed by the second piston and the balls 57, . Switches to 2 switching position.

When the spool 52 is switched, the pilot port Ac of the pilot switching valve 50 communicates with the exhaust port Rc, so the pilot air in the first pilot chamber 35 of the main valve 20 is exhausted to the atmosphere, and the piston 34 and rod of the main valve 20 are 32 is moved downward by the pilot air supplied from port Pb to the second pilot chamber 36, and the vacuum pressure valve body 30 closes the vacuum pressure valve seat 29 by the biasing force of the main valve spring 31, and the supply valve Since the body 27 opens the supply valve seat 26, the main switching valve section switches to the second switching position where the output port A and the supply port P communicate with each other, compressed air is supplied to the suction pad 3, and the article suction is released. be done.

When the electromagnetic part 61b of the switching valve 60b is de-energized, communication between ports Pb and Ab is cut off and ports Ab and Rb are communicated, so that the air in the second pilot chamber 36 passes through the second switching valve 60b to the atmosphere. is discharged. Therefore, the supply valve body 27 of the main valve 20 closes the supply valve seat 26 due to the biasing force of the main valve spring 28, so that the main switching valve returns to the neutral position where communication between the ports is cut off, and the suction Padded 3
returns to hibernation.

[Effects of the invention] In the present invention, the pilot switching valve member of the pilot switching valve is in the first switching position, the main switching valve part of the main valve is in the first switching position, and the output port is in communication with the supply port. When the pad is picking up a desired item, the mechanical detent mechanism maintains this switching position, so even if the electric switching valve of the pilot switching valve loses its valve function due to a power outage, etc. The main switching valve portion of the main valve can be held at the first switching position, so that the suction pad does not lose its ability to attract and hold articles.

In addition, since the pilot switching valve member of the pilot switching valve is switched by the control air output from the electromagnetic switching valve, it is smaller than when the pilot valve is a direct-acting type valve that is directly driven by an electromagnetic part. It can be done.

Furthermore, since there is no need for a separate solenoid for detent release as in the case of FIG.
The vacuum pressure control valve can be made simple and inexpensive.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the same operation as above, Fig. 3 is an explanatory diagram of the operation of a conventional vacuum pressure control valve, and Fig. 4 is an explanatory diagram of the operation of the prior art. be. 3...Adsorption pad, 4...Vacuum source, 5...Compressed air source, 20...Main valve, 24...Pressure receiving operation part, 5
0...Pilot switching valve, 52...Spool, 5
5... Mechanical detent mechanism, 60a, 60b...
Solenoid switching valve, P...supply port, A...output port, R...vacuum pressure port, Pc...pressure port,
Ac...Pilot port, Rc...Exhaust port.

Claims (1)

[Scope of Claim for Utility Model Registration] A vacuum pressure control valve comprising a main valve consisting of a 3-port 3-position switching valve and a pilot switching valve for supplying and discharging pilot fluid to the main valve, the main valve comprising: The main switching valve includes a supply port communicating with a compressed air source, an output port communicating with a suction pad, a vacuum pressure port communicating with a vacuum pressure source, a main switching valve part, and a pressure receiving operation part, A first switching position in which the output port is communicated with the vacuum pressure port by pilot fluid supplied and discharged from the pilot switching valve to the pressure-receiving operation part, a second switching position in which the output port is communicated with the supply port, and each port. The pilot switching valve has a pilot switching valve member, a pair of electromagnetic switching valves for driving the pilot switching valve member, and a mechanical detent mechanism. , when the pilot switching valve member is in the first switching position by one of the electromagnetic switching valves, supplying pilot fluid to the pressure-receiving operating part of the main valve to switch the main switching valve part to the first switching position; When the other solenoid switching valve is in the second switching position, pilot fluid is supplied to the pressure-receiving operating part of the main valve to switch the main switching valve to the second switching position.
A vacuum pressure control valve configured to switch to a switching position, and characterized in that the mechanical detent mechanism maintains a pilot switching valve member in a first switching position at the switching position even during a power outage. .